Film feed for sound recording and reproducing apparatus



' Dec. 23, 1941; I A, HERZK; 2,266,755

FILM FEED FOR SOUND RECORDING ANDREPRODUCING APPARATUS Original FiledApril 24, 1937 I 9 sheets-sheet 1 I I gvwvroa ATTORNEYS.

, m m'm lflllllllllllH g Dec; 23, 1941. L. A. HERZIG FILM FEED FOR SOUNDRECORDING AND REPRODUCING APPARATUS Original Filed April 24, 195'? 9Sheets-Sheet 2 INVENTOR ATTORNEYS Dec. 23, 1-941. A, HERZI 2,266,755

FILM FEED FOR SOUND RECORDING AND REPRODUCING APPARATUS Original FiledApril 24, 1937 9 Sheets-Sheet 3 z y INVQE'NTOR afl b&m-

ATTORNEYS Dec. 23, 1941. 1.. A. HERZIG 2,265,755

FILM FEED FOR SOUND RECORDING AND REPROPUCING' APPARATUS Original FiledApril 24, 1957 9 Sheets-Sheet 4 L. A. HERZIG Dec. 23, 1941.

FILM FEED FOR SOUND RECORDING AND REPRODUCING APPARATUS e sheets-Sheet 5Original Filed April 24, 1937 w H m m M 4 Dec. 23, 1941. A.HERZ|G FILMFEED FOR SOUND RECORDING AND REPRODUCING APPARATUS 9' Sheets-Sheet 6Original Filed April 24, 1937 w v E N R O n A 4 Dec. 23, 1941; L. A.HERZIG 2,266,755

FILM FOR SOUND RECORDING AND REPRODUCING APPARATUS Original Filed April24, 195 9 Shets-Sheet 7 I g g nullilllllllllllu INVENTOR ATTORNEYS Dec.23, 1941. I L. A. HERZIG 2,266,755

' FILM FEEf) FOR SOUND RECORDING AND REPRODUCING APPARATUS OriginalFiled April 24, 1937 9 Sheets-Sheet 8 ATTORNEYS L. A. HERZIG Dec. 23,1941,

FILM FEED FOR SOUND RECORDING AND REPRODUCING APPARATUS Original FiledApril 24, 1937 9 Sheets-Sheet 9 jj ya I] U U D 13 e ATTO R N EYS Z lNV,

qmmncxnmmm CIDEIDE] tracks on a film or for playing. anyselected partPatented Dec. 23, 1941 UNITED STATES PATENT OFFICE FILM FEED FOR. SOUNDRECORDING AND REPRODUCING APPARATUS Leonard A. Herzig, Jackson Heights,N. Y., as-

signor to Lon-Ga-Tone, Inc., New York, N. Y.,

a corporation of New York Original application April 24, 1937, SerialNo.

138,751. Divided and this application June 5,

1940, Serial No. 338,844

12 Claims.

This invention relates to a photographic sound recording and reproducingsystem and is a division of my copending application Serial No.

138,751, filed April 24, 1937, now Patent #2,2l5,468, issued September24, 1940.

The principal object of the invention is to pro- .vide a new andimproved apparatus for continuously and uninterruptedly recording on orreproducing from a plurality of parallel sound paratus for recording orreproducing sound for broadcasting purposes, for assemblies, for recordlibraries or for other purposes for which phonographs or film haveheretofore been used., An important, feature of the recording andreproducing system disclosed and claimed in my abovementioned Patent#2,215,468, with which the film feeding apparatus of the presentinvention is adapted to be used, resides in the use of a comparativelyshort film containing a plurality of sound tracks which are playedsuccessively. A standard width 35 mm. film may, for example, have somethirty different sound tracks which .are joined by loops so arrangedthat'the scanning light follows the loops on the changeover withoutaudible variation. The film is held on two reels,- as hereinafterdescribed, and is fed first in one direction and then in the other forscanning each of the difierent connected tracks which constitute thesound record.

In a preferred embodiment of the invention, hereinafter described, thefilm is fed past a sound gate by a pair of sprockets which arereversibly driven in unison. A pair of driveshafts preferably havingsuitable vibration dampeners are continuously driven in oppositedirections and a novel electrically operated clutch mechanism isprovided to selectively connect the sprockets in-driving relationship tothe respective driveshaf-ts. This mechanism is automatically operated bythe@ film itself whenever the end of a sound track has 50 been reached,or it may be operated manually. In the preferred embodiment, disclosedand claimed in said Patent #2,2l5,468,"a sensitive'and accurate controlof the reversing mechanism is obtained by changing the grid potential ofa 55 space dischargetube by the capacity effect of a conducting bar orstrip which is formed in or attachd to the film adjacent the ends'of thesound tracks, the control being effected when the conducting stripreaches a predetermined point with respect to the sound gate.

Another'feature resides in the provision of a rewind mechanism forrewinding the film at a higher speed when single sound tracks or groupsof tracks are to be used for individual selections.

In one embodiment a manual switch is provided for stopping the film andfor rewinding. The rewind is stopped automatically, however, when theconducting strip on the film reaches a designated point on the filmgate. Means are also provided to prevent the rewind mechanism fromoperating except when the main drive clutches are released. 7 In theform shown herein for purposes of illustration the rewind is effected bya friction wheel driven by a flexible driveshaft and brought intodrivingv position by a rewind solenoid.

These and other features and advantages of" the invention will bedescribed in connection with the accompanying drawings, in which:

Fig. 1 is a top plan view of my preferred apparatus as adapted forrecording purposes;

Fig. 21s a vertical section taken on line 2-2.

of Fig. 1;

Fig. 3 is a transverse section taken on line 3-3 of Fig. 1, showing thedriving, reversing and rewinding mechanisms;

- Fig. 4 is a detail section on line 4-4 of Fig. 3

Fig. 10 is a circuit diagram of the reproducing unit shown in Fig. 8;Fig. 11 is a sectional view taken on line ll-ll of Fig. 2, showingdetails of the mechanism for controlling the position of the apertureplate:

Fig. 12 is another sectional view of said control mechanism,.- taken online l2l2 of Fig. 2;

Fig. 13. is a horizontal section taken on line 13-13 of Fig.3,illustrating the sound gate and the threading and adjusting mechanismfor the film; I

- tension of the take-up mechanism;

Fig. 17 is a view similar to Fig. 13, showings.

' modification of the film driving mechanism;

Fig; 18 is a plan view of a strip of film, showing the electriccontactsat both ends for controlling the reversal of the film; and I Fig. 19 isa diagram of the electrical circuits of the apparatus.

In the following description and in the claims certain specific termsare used for convenience in referring to various details ofconstruction, but it will be understood that these terms are to be givenas broad an interpretation as the. state of the art will permit.

The machine shown in the drawings comprises a top plate I (Figs. 1 to 3)on which are mounted a pair of reels 2 carrying the film 3 whichcontains the sound record. This film may be of the usual type employedin motion pictures and is shown more in detail in Fig. 18

as having a plurality of parallel sound record tracks 4 which extendover substantially the entire length of the film and are joined at theirends by loops 5. The successive tracks are recorded with the fihn movingin opposite direc- Itions sothat a continuous sound record is ,ob-

The conducting-strips 1 are used for automatically reversing the film 3in a manner hereinafter described. It is to be understood that the filmitself may be of any suitable or standard construction. The sound tracks4, however, are

Take-up mechanism The take-up mechanism for driving the reels 2 is shownin detail in Figs. 2 and 5 and includes a motor 20 which is mounted onsuitable brackets 2| supported on the base 22 of the machine. The motor20, through a reduction gear 23, drives pulleys 24 in oppositedirections. These pulleys carry belts 25 which drive the pulleys 26.Each pulley 26 is mounted on a sleeve 21 which is rotatably held in abearing 28 supported by a bracket 29 which is attached to the top plateI of the machine. Each sleeve 21 carries a disk 30 on which a frictiondisk 3! of suitable friction material is supported as shown in Fig. 2.Engaging thisfriction disk 3| isa. driven disk 32 which is keyed, as bykey 33, to a shaft 34 which extends through the sleeve 21 and isrotatable therein. The shaft 34 extends through a bearing'35 which isformed on the bracket 29 and supports a reel 2. The reel is locked toshaft 34 for rotation therewith by means of a lever 36 which is adaptedto fold over onto the top of the reel for the above purpose.

For varying the amount of friction I provide a pair of pivoted arms 40which are pivoted at M to ears 42 carried on the top plate I of themachine. Each arm 40 is provided at one end with a fork 43 carryingadjustable pins 44 which seat in a rotating collar 45. A spring 46 isseated around the shaft 34 between the collar and the driven disk 32 toapply pressure to said disk dependent upon the amount of comthe shaft52.

pression of said spring. The other ends of the arms 40 are connected bypins 50 to a collar 5| which is carried on shaft 52 extending through abushing 53 attached to the top plate I of the machine. The shaft 52 isprovided at its end through the bushing 53. and thereby cause pivall ofexactly the same length and the loops 5 are aligned in the sametransverse. section of the film so that the scanning my can be caused toexactly follow these loops on each reversal of the film. This exactnessin. the position of the various loops is obtained by the controlmechanism hereinafter described.

Referring again to Figs. to '3, the film 3 is passed between the reels 2River a pair of drive film gate II.

The film gate H supports the film in a position to be scanned by lightfrom a light source I5 whichis focussed by a telescope or lens system I5onto the film. The film gate II, adjustable idler rollers I3, lightsource I5, telescope I6 and associated mechanisms are mounted as a uniton panel l8 which is adapted to be removed from the' topplate I and tobe replaced by a reproducing unit when the machine is used forreproducing sound from the film.

otal movement of the arms 40 for varying the pressure of the springs 46.i

In the above-described take-up mechanism each lower disk 30 is driven bya belt 25 from a pulley, 24 which in turn is driven by' the motor 20.The lower disk 30 drives the upper disk 32 34, drives the shaft and thereel 2 which is attached thereto. If desired, an index may be I2 or,

provided by mounting a disk 50 at the end of the shaft 52 within theknob 55 and visible through a slot 6| in said knob as shown in Fig. 16.The disk accordingly moves axially and, by its position, indicates theadjustment of the springs 46. A suitable scale may be provided on theknob 55 to register with the disk v6!) for the foregoing purpose.

It has been found that the driving force required for the reels 2depends upon the weight of the reels, more force being required fordriving a heavy reel than for a light reel. This weight is proportionalto the length of the film, consequently the adjusting knob 55 may begraduated directly in feet of film so that an operator, knowing the feetof film -on any given reel, can adjust the pressure of the spring 48accordingly. It. is to be understood that the take-up mecha- Drive forfeed sprockets Feed sprockets l8 are driven from the motor 28 by meansof a driveshaft 85 attached to the motor (Figs,,2, 3 and and carrying aflywheel 88 by which irregularities in the drive are largely eliminatedand hunting of the motor is prevented. The shaft 65 is connected by aflexible coupling 81 to a helical gear 68 which drives a pair of helicalgears 89 at the same speed and in opposite directions. The gears 69 arerotatably mounted on sleeves I8 which are journaled in bearings IIcarried on brackets I2 which are attached to the top'plate I and-thebase 22 of the machine in a convenient manner. The gears 69 each carry aspider I3 having a plurality of arms I4 (as shown in Fig. 4) which arecon-- nected by springs 15 to pins I8 which are formed part of sleeve 82which is journaled in bearings 83 carried by the bracket I2. Each sleeve82 carries a gear 84 meshing with a gear 85 whichis attached to \theshaft 88 on which the drive sprocket I8 is fixed. The two gears 85 arepreferably split gears of any suitable type designed to eliminatebacklash or play; and these gears are connected by an idler gear 81 soas to operate in unison and at a uniform speed.

For operating the clutch'member 88 there is provided a rod 98 whichextends through each sleeve I8 and is provided with a collar 9'I whichis positioned below the upper toothelement 8| of the clutch 88' and isadapted when elevated to raise the upper tooth element sufficiently todisengage the toothfjrom the lower element I9. The rods 98 are connectedto a pivoted arm 92 which is pivoted at 98 between the arms of a doublebracket 94 supported on thebase 22 as shown in Fig. 3. The bracket 94also provides bearings 95, in which the .driveshaft 85 is journaled. asshown in Fig.. 2.

The ends of the arm 92 are attached to cores 98 of solenoids 99 whichare arranged to control the position of the arm .92. v The arrangementis such that when one of the solenoids 99 is energized the core 98 andthe .rod 98 attached thereto are pulled downwardly, thereby causing thecorresponding clutch 88 to engage while disengaging I the oppositeclutch. Thedirection of drive of the sprockets I8.is accordinglydependent upon the particular solenoid 99 which is energized at anyparticular time. The motor 28 and the fi'y-' wheels 11 are rotatedcontinuously. When one of the clutches is displaced, however, thecorresponding driveshaft picks up ,and drives the sprocket I8. Thesprings I5 provide a loose coupling between the respective flywheel I1and the associated gear 69 so that-each spider forms a mechanical filteror vibration dampener to eliminate minor vibrations or variations in thedrive from being applied to and effecting the uniform rotation of thefeed sprockets I8. By interconnecting the driveshaft for the two feedsprockets I8 by means of the. gear 81 any play when one of the solenoidsis energized. The lock nuts 98 on rods 98 hold these rods in positionand permit vertical adjustment of the upper halves of the associatedclutches 88.

In order to maintain the clutch 88 engaged after the rod 98 has beenmoved downwardly by energization of the solenoid 99 and withoutrequiring the solenoid to be continuously energized, a suitable holdingmeans may be provided.

In the embodiment shown, this holding means I may compriseelectromagnets I88 which are suitably mounted on the frame of themachine and In certain instances it is desirable to rewind the reel at ahigher rate of speed, as for example when the various film tracks areused for inde-- pendent selections or programs. In that event when oneselection has been completed it may be desired to rewind the filmpreliminary to playing a second selection. This may be accomplished byproviding a high speed rewind, one form of which is shown in Figs. 3 and14. In the embodiment shown the rewind comprises a flexible driveshaftI88 which is driven by a gear -I89 meshing with one of the helical gears69. The flexible driveshaft I88 is attached in driving re lationship toa friction disk II8 which is adapted to be brought into drivingengagement with a second friction disk III which is mounted on the shaft86 of the corresponding feed sprocket I8 which is normally driven by thegear 89 from 4 which the power is taken. The friction disc H8 is mountedon a housing II2 which is attached by a block II3 to the flexibledriveshaft I88 and is mounted for rotation on a shaft I I4 by means of acollar H5. The shaft H4 is pivoted at I It to ears I" attached to thetop plate I of the machine. The pivotal position of the shaft H4 isdetermined by an arm I28 having a forked end I2I which is adapted-to beclamped by. a screw I22 about the arm II4'and at its other end. is

attached to a rod I23 which engages the core' I I8 is brought out ofengagement with the disk or lost motion is prevented and the gears areRecording head The recording head is mounted as a unit on the panel I8as shown in detail in Fig. 6. This recordinghead carries an elongatedglow lamp I4I comprising the light source, a telescope-tube I8 and thefilm gate II together with associated mechanisms hereinafter described-The filmgate II comprises a circular housing I45 mounted in a cup I46which is attached to the panel I8 by suitable means such as screws I41.A pair of rotating rings I48 and I49 are mounted on the housing I45.These .rings are provided with.

shoulders I58 and I5I- respectively, between the cup I45. The lip I54serves to prevent axial motion of the ring I48.

The upper ring I49 is shown as insulated from the housing I45 for a.reason to be described. For

this purpose the upper ring is attached to an in-.

nor rotating ring I80 from which it is separated by a ring I6l ofinsulating material. The ring I80 is mounted for rotation on the upperpart of the housing 145 and is provided with a flange I62 which bearsagainst and is confined by a flange I83 formed on a locking ring I64which is attached to the housing I45. Ahelical spring IE is seated in asuitable recess in the housing I45 and bears against the top of theflange I62 to prevent axial movementv of the ring I49. The

flange I83 is spaced from the ring I49 so as to avoid making electricalconta'ct'therewith. The ring I49 is thus insulated by the ring I8I fromthe housing I45. For making an electrical contact with this ring aspring brush I10 is providedwhich bears against the surface of the ringI49 and is attached to the locking ring I54 by means of an insulatingbushing I1I. An electrical connection may be made to this brush I10which is fastened to the ring. I64 by screw I12. It will be noted thatthe film 3 is supported on the rings I48 and I49 as it passes over thehousing I constituting the film gate II and is thereby held in properposition to receive the scanning ray.

The glow lamp I is preferably formed with elongated electrodes I15 andI16 as shown in Fig. '1. These electrodes are made substantially longerthan the area of the film '3 which is to be scanned so that light may befocussed over the entire width of the film with substantially equalintensity. In the form shown the electrode I15 is channel-shaped andconstitutes the cathode, whereas the electrode I18 is in the form of alooped wire registering with the edges of the channel-shaped electrodeI15 and constitutes the anode. This elongated construction permits auniform light intensity to be radiated from a substantial portion of theglow lamp. This light is focussed by a suitable lens system carried bythe telescope tube I9 over the entire width of the film 9. In the formshown the telescope tube I8 carries a pair ofcylindrical lenses I18 theaxes of which extend in a direction transverse to lens I19 and arearranged so-as to concentratethe rays received from the glow lamp I 4|over an area extending the full width of the film 3. This light isconcentrated and focussed in a narrow vertical band by means of thecylindrical lens I19 which is arranged with its axis extending in avertical direction. The arrangement issuch that this band whichconstitutes the scanning ray is preferably not over .0003" in width;.The telescope tube I8 may be provided with a lug I80 which isadjustably supported on a screw I8I which is held in bracket I82attached to the pane1l8.. Jidjustment of the screw I8I' moves thetelescope tube and the-entire lens system axially so as to permit properfocussing of the light rays from the glow lamp I4 I. g

In order to confine the ray to one sound track .of the film at a time anaperture plate I is provided between the glow lamp MI and the telescopetube I6. This aperture plate is formed with a narrow slit I88corresponding in width to the width of one of the sound tracks asindicated in Figs. 6 and 12 and is mounted for sliding vertical movementin a shield I81 which is carried by the telescope tube I8. The apertureplate I 85 is provided with a downwardly extending portion 88 carryingrack I89 which meshes with a gear I90.' The gear I90 is adjustablyfastened to a shaft I9I which extends through the front wall I92 ofpanel I8 and carries a knob I93 by means of which the position of theaperture plate I85 may be adjusted. It will be noted that the gear I90is sufficiently long to permit slight axial movement of the rack I89 asthe aperture plate I85 and telescope tube I8 are acUusted for focussingthe light in the mannerdescribed above.

For shifting the aperture plate I85 between successive film tracks apawl and ratchet mechanism is provided which comprises a ratchet gearI98 (Figs. 6 and 11) carried on the shaft I9I and held between bearingsI99 of said shaft which are carried in bracket 200 attached to the panelI8. A pawl 20I is pivoted to a split arm 202 which is journaled on theshaft I9I on opposite sides of the ratchet gear I98as shown in Figs. 5and 11. The pawl 20I rests against an adjustable stop 204 (Fig. 11)which is carried by an arm 205 (Fig. 5) attached to the bracket 200. Thepawl 20I is normally held out of engagement with ratchet gear I98 by aspring 208. A locking pawl 201 is pivoted as at 208 on an arm 209attached to the bracket 200 and is moved toward the ratchet wheel I98 bya spring 2"]. Adjustable stop 203 is carried by the arm 202 toengage thelocking pawl 201 and hold the same out of contact with the teeth of theratchet wheel I98 when the wheel is not actuated. The arm'202 isattached to core 2 of a solenoid 2I2 which is adapted when energized tocause the pivotal movement of the arm 202 for stepping the ratchet wheelI 98 around one tooth. Suitable means, such as a spring 2I3, may beprovided for returning the arm 202 to the position shown in Fig. 11 whenthe solenoid is deenergized.

For holding the" ratchet wheel I 98 in a given position a disk 2I5(Figs. 6 and 1-1) is mounted on the shaft I SI and is provided with aplurality of peripheral teeth 2I8 against which rollers 2| 1 rest. Theserollers are carried on leaf springs 2 I8 which are attached to-the panelI8 by means of screws 2I9. The rollers 2I1 are adapted to engage thedisk 2I5 between the teeth 2IIi so as to secure the ratchet mechanism inany adjusted position. It isfto be noted that when the solenoid 2I2 isdeenergized the arm 202 is in the position shown in Fig. 11 and thepawls 20I and 201 are held out of engagement with the ratchet wheel I98by the stops 204 and 203, respectively. The shaft I 9I may then berotated by means of knob I93. This knob is preferably provided withgraduations 220 which register with a suitable index on the front I92 ofpanel I 8- to indicate the position of the aperture I86. This index may,for example, be numbered to indicate the number of the sound track whichis in position to be played or recorded. This hand adjustment may beused, for example, when it is desired to set the machine to record on agiven sound track. The dial likewise turns with the shaft 181 during theautomatic operation of the machine and thereby indicates the position orthe scanning ray at any particular time.

It is to be understood that the entire ratchet mechanism including thesolenoid 212 may be removable as a unit with the panel 1-8.v Suitablequick detachable plugs, not shown, may be provided for breaking theelectrical circuit when the recording head is thus removed.

Asishown in Fig. 6, a shield 225 having an aperture 225 in alignmentwith the telescope tube 15 may be positioned over the glow lamp 141 toprevent light, rays from going any place except through the apertures225 and 234, the latter of which is used for monitoring purposes asshown in Fig. 1 and as described below. This shield may have suitablespring clips 221 by which it is securely seated over the glow lamp. Theglow lamp may be provided with a suitable vibration dampening socket 228by which it it connected to a supply circuit in the usual manner.

The glow lamp is actuated as indicated in Fig. '1 by the output circuitof an amplifier 238 which is fed in the usual manner by a microphone 231or by any other suitable pickup means. In order to assist in listeningin, a photoelectric cell 233 is mounted on the panel 18 as indicated inFig. 1 in a position to be energized directly by the glow lamp 141. Theshield 225 is provided with a slit 234 opposite the photoelectric cell233 as shown in Fig. 1 so as to permit rays from the glow lamp to passtherethrough. The photoelectric cell 233 is preferably madewith-elongated elements 235 which extend in an axial directionsubstantially coextensible with the elongated elements 115 and 116 ofthe glow lamp 141. This photoelectric cell 233, may be connected withthe input circuit of a standard amplifier 238 the output circuit ofwhich may be connected to a suitable reproducing device 231, such as a.oud speaker, earphones or the like. It will be evident that thephotoelectric cell could be nounted in other positions; for example, it,could are mounted in back of or within the film gate in which case itwould receive only the scanning'ray which has passed through the film.

It is to be understood that the optical system within the telescope tube15 may be varied as desired. In general the optical system should beiesigned to focus the light in the form of a fine vertical band equalto'the entire width of the lilm so that the aperture plate. in movingvertically can cut ofi all of the light except that corresponding to theselected sound track. In this way it is only necessary to move theaperture plate in shifting from one sound track to another. Theremainder of the mechanism remains stationary. In the embodiment shownan upward movement of the aperture plate will cause a downward movementof the scanning ray at the film and vice versa. The lens system,however, could be arranged to produce parallel. rays in which case themovementof the aperture would correspond to the movement of the scanningray at the film.

In the above-described mechanism the scanning rays may be shifted fromone sound track to the next with great rapidity inasmuch as it is onlynecessary to move the comparatively light weight aperture plate. Themovement can also at the end of each sound track.

Reproducing head The machine is so constructed that the reproducing headshown in Fig. 8'is interchangeable v with the recording head shown inFig. 6. -The reproducing head comprises a panel 245 which is adapted toseat on and be secured to the top plate of the machine in place of thepanel 18 as shown in Fig. 1. This panel 245 carries a cup 245 which isattached thereto by .suitable screws 241 and supports a housing 248which forms the film gate. The housing 248 is provided with acylindrical bore 249 in which the photoelectric cell 250 is adapted tobe positioned. It is also provided with an opening251 which extends over255 between which the film 3 is guided. Thev ring252 is rotatablymounted on the housing 248 and is provided with a flange 255 whichengages beneath a shoulder 251 in saidhousing for positioning the ring.

Th ring 253 is mounted on a ring 258 ,irom

which it is separated by an insulating ring 259.

The ring 258 is rotatably mounted on the housing 248 and is providedwitha flange 250 which is engaged by the flange 251 ,formed on a lockingring 252. the film guide flange-255 in constant contact with the upperedge of the fllm during operation even though wear should take place;The flange 251' terminates short of the' ring 253 so that this ring iselectrically insulated from the housing..

Contact is made to the ring 253 by means or a flexible brush 254 whichis attached to an exconnection to the photoelectric cell 250.

tension 255 of the housing and is insulated therefrom by bushing 255.The extension 255 carries a cap 251 which closes the top of the housingand forms a socket for making the electrical The socket may be oi anyconvenient or standard construction for this purpose. Suitable spacingelements 258 of soft material such as rubber may be provided at the"bottom of the housing 248 and within the central bore 248 so as tosupport the photoelectric cell 258 and to prevent vibration' from beingimparted thereto.

The housing 248 is also provided with a vertical bore 210 in which anaperture plate 211 slides.

. The aperture plate is provided with an aperture lar ratchet mechanismwhich has been given corbe accurately controlledby the automatic timingmechanism, hereinafter described, so asto responding reference numeralswith primes at" flxed thereto, and the description of these parts willaccordingly not be repeated. It is to be understood that the entireratchet mechanism of Fig. 11, including the am 282, the solenoid 212 andassociated parts is duplicated in the reprosynchronize exactly with thereversal of the film The spring 253 isemployed to keep ducing head oiFig. 8 and this reproducing head is removable as a unit to replace thecorresponding mechanism in the recording head.

The reproducing head is also provided with a socket 280 in whichexciting lamp 28! is held. This exciting lamp is provided with anelongated filament 282 as shown in Fig. 10, which is of such length thatrays of equal intensity are propagated over the entire apertured area ofthe telescope tube to be described. This filament 282 maybe held inposition by a spring 283 which is adapted to maintain the filament tightunder all conditions. This is important inasmuch as the image of thefilament is to be focussed onto the film and any variations thereofwould cause corresponding distortion in the reproduction.

The reproducing head is provided with a telescope tube I6 which issimilar in construction to the telescope tube i6 of Fig. 6 and carries asuitable lens system. The elements of the tube and the lens haveaccordingly been given the same reference characters with primes aifixedthereto and a description thereof will not be repeated.

The lenses in general are adapted to focus an image of the elongatedfilament 282 on the film 3 as the film passes the opening 25I in thehousing 248. The image must be of equal intensity across the entirewidth of the film inasmuch as it is to cooperate with the various soundtracks thereon. The aperture plate 2" cuts off all of the rays passingthrough the film except the rays through the selected sound track whichare permitted to pass through the aperture 212 and to be impressed uponthe photoelectric cell 250. As the aperture plate is stepped upwardly ordownwardly by means of the ratchet mechanism the scanning ray is thusshifted from one sound track to the next in a manner similar to thatdescribed in connection with the aperture plate I85 of Fig. 6. In thereproducing head, however, the scanning rays are continuously applied tothe entire film width and the aperture plate is positioned between thefilm and the photoelectric cell. It is to be understood that theaperture plate could be placed in some other position if desired. Forexample, the aperture plate could be located between the exciting lamp28! and the telescope tube as shown in Fig. 6, or it could be locatedbetween the telescope tube and the film 3.

Guide rollers Referring to Fig. 1, it is noted that the springpressedguide rollers [2 are provided for absorbing the shock on the film duringreversal. Each of these guide rollers is shown as mounted on an arm 288which is pivoted by means 015 a screw 289 and is held by a spring 290 incontact with the film 3. Stop 29| may be used to limit the movement ofthese arms. The adjustment of the spring tension should be such that therollers i2 are adapted to take up the shock when the film is reversedand prevent tearing of the film. It is to be noted in this connectionthat when the film is reversed one of the reels 2 will be full andcorrespondingly heavy and will be rotating in a direction to wind up thefilm thereon. Whenjthe film is suddenly reversed by reversal of thesprockets Hi the inertia of this full reel must be overcome and the reelstarted to rotate in the opposite direction against the drag exerted bythe take-up mechanism. The pressure of the springs 290 is adaaeemss armsare returned by the springs 290 when reversal occurs in the direction ofthe reel for takjusted so as to accomplish this, the arms 288 swinginginwardly as the film tightens, and these ing up. It is to be understoodthat suitable adjustment may be provided for varying the pressure of thesprings 290 if desired.

Idler rollers H are mounted in the usual manner to holdthe film incontact with the drive sprockets l0. Idler rollers 13 are mountedbetween the feed sprockets I0 and the film gate in which these idlerrollers are attached to hold the film in contact with the feed sprocketsand also to maintain the film in engagement with a predetermined sectorof the aperture plate as shown more in detail in Fig. 13. In Fig. 13idler rollers iii are shown mounted so that they may be adjusted tocompensate for variations in length of the film due to temperaturechanges, etc., the mounting beingarranged so that this adjustment can beeflfected without changing the arc of contact of the film with the filmgate. This latter feature is of importance inasmuch as the reversal ofthe film is automatically efiected when the conducting strip I thereonengages the film gate; consequently any variation in the arc of contactwould alter the timing of the control mechanism. In the embodiment shownthis adjustment is obtained by mounting each idler roller 13 upon ashaft 295 (Figs. 13 and 15) which is held in an elongated slot 296 in aplate 29'! attached to the panel l8 in the case of the recording head,or to the panel 245 in the case of the reproducing head. A bushing 298is disposed about the shaft 295 and is adapted to be clamped against theplate 291 by means of a thumb screw 299. The roller I3 is mounted forfree rotation on this bushing 298.

The slot 296 is elongated in a direction parallel to the line of feedoithe film toward the film gate, that is, in a direction parallel to atangent to the film gate at the point where the conducting strip I onthe film comes into contact with the film gate as shown in Fig. 13,Con-; sequently adjustment of the idler roller 13 along this slot 296does not change the angle of the feed of the film past the sound gateand does not change the timing of ,the control mechanism. It is to beunderstood, 0! course, that other suitable adjusting. means may be usedif desired in place of that shown and described above.

Film driven} Fig. 17

Fig. 17 shows a modified form of film drive which may be used in placeor the two Ieed sprockets 10. In this embodiment the film gate H isconstructed in the manner described above.

In place 01 the two feed sprockets l0, however. there is provided asingle feed sprocket 305 which is of sufiicient diameter so that thefilm may contact over two separate portions of the surface thereof. Thissprocket 305 is driven by gear 306 which meshes with the gears 05 asshown in Fig, 17. ing engagement witha portion of the surface of,the'feed sprocket 305 with which it is held in contact by adjustablerollers I01. Thence the film passes around the film gate II and indriving engagement with another portion. of the sprocket 305 with whichit is held in contact by adjustable rollers 308. The rollers 901 and 900are mounted so that they can be displaced to permit the film to bethreaded over the sprocket 305. In this embodiment the film is driven toand from the film gate by means of a'single sprocket. This constructionmay be preferred The film 3 passes in drivply line.

which cooperate with the blade 331, are con-- in certain instances asfor example in a light machine where it is desired to reduce the numberof parts as much as possible. It is understood that the machine isotherwise similar to that described above.

Control circuit The control for reversing the drive and for stepping theaperture plate from one sound track to the next is shown in Fig. 19.This circuit shows an A. C. supply line 310 driving the motor 20 andfeeding the primary of the transformer 311 through a switch 312 by whichthe entire system may be disconnected as desired. The secondary 313 oftransformer 311 is connected across the anode and cathode of a spacedischarge tube 314 of standard construction such as a grid 'glow tube. Arelay 315 is connected in series with one of the leads from thesecondary 313 to-the tube 314 in such a way that the space current ofthe tube passes through relay left side' of the arm 92, as well as tothe left hand solenoid 99 and thence through lead 341 to a lower contact342 which is adapted to be engaged by the arm 336 when the'arm 92- hasbeen depressed by actuation of the right hand solenoid 99. When startingthe machine the arm 92 is in a neutral position due to the balancingsprings 130, which allows theclutches to remain in neutral position. Themotor is then started and allowed to come up to speed. Thereafter theswitch 312 is closed to energize the control circuit.

The switch 312 has a make, break, and then make circuit whereby in theevent that the arm 328 of impulse-relay 321 is not closing contact 336an impulse will be transmitted through contact arm 365 and impulse relay321 causing arm 328 to close contact 330 for starting purposes.

This safety factor insures that arm 326 will al- 315 and energizes thesame. The tube 314 is provided with a grid 311 which is adjustablyconnected to the cathode of the tubethrough an impedance such as avvariable condenser 321. The biasing potential on the grid 311 may beadjusted by condenser 321 to a value sufiiciently negative to block thetube. When the capacity hereinafter described is added to the gridcircuit, .however, the potential of the grid is altered sufiiciently topermit passage of space current through the tube. For this purpose thegrid 311 is connected to an insulated ring 149 of the recording head orthe insulated ring 253 of the reproducing head by means of therespective contact brushes 110 and 264.

The bottom ring 148 of the recording head or the bottom ring 252' of thereproducing head is grounded to the unit. Consequently when the metallicstrip 1 of the film engages these rings the effect is to add capacity tothe grid circuit thereby changing the grid' biasing potentialandpermitting space current to flow. This space current energizes relay 315which thereupon attracts its armature and closes its contact 325,

completing the circuit from one side of the supply line 316 through animpulse relay 321 and back to the other side of the supplyline. Therelay 321 is thus connected across the line and is energized thereby.The relay 321 is of the impulse type which is adapted to moveitsarmature 328 alternately to close contact 329 or 330 at successive.actuations of the relay.

A switch such as a push button 320 may be connected in parallel to thecontact points 325 of relay 315 by which the electrical circuit may bemanually operated to actuate the relays when desired. The-contacts 329and 330 are connected respectively to blades 332 and -33! of atriplepole triple-throw switch 333. The armature 328 is connected by aline 334 to one side of the sup- Contacts 335 and 336 of switch 333,

nected together and to one of the solenoids 99 as well as to a suitablerectifier such as a rectox unit 361 which is connected to a holdingelectromagnet 100. In the embodiment shown-these contacts are connectedto the right hand solenoid 99. The circuit of this solenoid is completedthrough a contact 331 engaging an arm 338 carried on the arm 92. The arm338 is connected by a lead 339 to the opposite side of the supply line.The left hand contact 349 for the blade 332 is connected to both arectox unit 363 which supplies the holding electromag'net. 163 on theways he in the correct position for moving the film in the one directionat starting time. The arm 326 is now making contact with contact 339 asshown in Fig. 19. The grid glow tube 314 is normally blocked and doesnot pass current. The relay 315 is, therefore, deenergized and is onlyenergized when the conducting strip 1 of the film makes contact with theabove-mentioned rings of the iilm gate, whereupon the potential on grid311 of tube 314 is altered thereby allowing space current to pass. Thisspace current passing through relay 315 energizes the same and causesthe relay to close contact 325 thereby completingthe circuit through andenergizing the impulse relay 321 to shift the arm 3211, thereby openingcontact330 and closing contact 329.

The contact 329 supplies current through blade 332 and contact 340 ofswitch 333 to the rectox unit 363, which I shall refer to as a holdingcurrent, and also to the-left-hand solenoid.99, the circuit to which iscompleted through contact 342 and arm 338. Energization of the left-handshift the arm 92.. However, holding current supplied through rectox unit363 is supplied to the associated electromagnet 106 as shown in Fig. 19.

The film is now running in the reverse direction, and, when it has againreached the end of its travel so that the opposite conducting strip 1contacts with the above-mentioned rings on the fihn gate, a circuit isagain completed which energizes relay 315 and thereby again energizesimpulse relay 321; This energization of relay 321 opens contact 329 andcloses contact 330, thereby completing the circuit through blade 331 ofswitch 333 to the rectox unit 361 as well as to the righthand solenoid99, contact 331 now being closed. This energization of theright-hand'solenoid 99 again actuates arm 92, reversing the positionthereof and reversing the direction of drive in the manner describedabove. It will be noted, therefore, that each successive engagement ofthe conducting strips 1 with the rings of the film gate causes reversalof the drive. In order to actuate the ratchet mechanism in synchronismwith the reversal of drive, the solenoid 212 of Fig. 11 is connected toone side of the supply line by lead 339 and thence by contact 345 to thethird blade 346 of switch 333 which is connected by lead 341 to contact325 of relay 315. Each energization of relay 3I5 which closes contact325 accordingly completes the circuit through solenoid H2 and causes theratchet mechanism to step the aperture plate to its next position. Theshifting of the aperture plate on the reversal of drive is accordinglyaccurately synchronized so that, in recording, the successive soundtracks are joined by uniform loops as shown in Fig. 18, and, inreproducing, the scanning ray follows the path of these loopsias it isshifted from one sound track to the next. In this way any break in thesound is avoided. The reversing and shifting of the aperture plate takesplace so rapidly that not more than one cycle of sound energy is lostand this is not sufiicient to produce any audible effect in thereproduced sound.

In some instances the sound tracks, instead of being continuous asdescribed above, may be arranged so that a plurality of selections orprograms are incorporated on the same film. A different selection may,for example, be recorded on each sound track. In this event the tracksmay all be recorded in the same direction and when the selection hasbeen completely played it is necessary to stop the machine and rewindthe film prior to the playing of the next selection. By means of theconnections shown in Fig. 19 the film may be stopped for the abovepurpose by shifting the triple-pole switch 333 so that blades 33I and332 engage the second contacts. The second contact 350 is not connectedto any electric circuit. Therefore, when arm 328 engages contact 329 noelectrical circuit is made through blade 332, hence rocker arm 92 ismoved to a neutral position by means of springs I30 causing the clutchmechanisms to disengage and bringing the film to a dead stop. However,

in the event the record referred to above is a short record and manualoperation is desired to i stop this record from running to the end ofthe film, push button 320 may be used to energize impulse relay. 321 sothat the above-mentioned circuit is opened. It is'to be noted thatcontact 331 is closed while the arm 92 is in neutral position and whenthe right end of arm 92 is in elevated position. The machine can thus bealternately started and stopped by button 320.

In order to actuate the high speed rewind, the rewind solenoid I25 isconnected from one side of the line to lead 339 through a switch 35I toa third contact 352 adapted to engage the blade 332 of switch 333. Afterthe machine has been stopped in the .manner described above, switch 333is shifted to a third position to close contact 352 thereby completingthe circuit from contact 329 through blade 332, contact 352 and switch35I, to the solenoid I25,-thus causing the rewind mechanism shown inFig. 14 to be actuated for rewinding the film. The switch 35I isassociated with an arm 353 which is carried by arm 92 and is adapted toopen the circuit whenever arm 92 is out of neutral position, therebypreventing accidental operation of the rewind mechanism when either ofthe clutches is engaged.

In order to automatimally stop the machine when the film has beenrcwound, the conducting strip I actuates the relay mechanism asdescribed above, thereby opening the electrical circuit so that nocurrent can pass to any solenoid, and allowing the balancing springs I30to bring arm 92 to neutral position. If switch 333 is then returned toits second position the arm 33I closescontact 336 thereby energizing theright hand solenoid 99 and causing the machine to again operate. Themachine will then operate until another impulse closes contact 329 ofimpulse relay 321 which then opens the electrical-circuit through blade332, allowing arm 92 to again be neutralized by springs I33.

Summarizing the above, it is noted that with switch 333 in the positionshown in'Fig. 19 the third position the high speed rewind mechanism isoperated when contact 329 is closed to complete a circuit throughsolenoid I25 and the machine is stopped when contact 333 is closed todeenergize the circuit allowing springs I30 to again neutralize rockerarm 92.

It is evident, therefore, that any desired combination of manual andautomatic control can be obtained by the above-described system. It isfurther to be understood that only so much of the circuit has been setforth as is necessary to an understanding of the invention. Variouscondensers are connected across the relay contacts in the usual mannerto prevent sparking. Other control and adjusting features may beincorporated therein in a manner understood in the at.

Operation The operation of the various elements has been describedabove. It is to be noted that the machine as a whole is intended tooperate with a multiple track film for continuously playing the entiresound record or for selectively playing certain individual sound recordtracks. The machine is adapted to be' used either for recording orreproducing by the simple expedient of providing separate andinterchangeable recording and reproducing heads, both of which aremountedas a unit and may be removed from the machine with a minimumamount of labor and time. The film is fed from one reel, over the drivesprockets and film gate and onto the opposite reel. The drive sprocketsIII are actuated in unison by the'driving mechanism. shown in Figs. 2 to5, the direction of drive being controlled by the'position of arm 92which actuates the clutches 80. With arm 92 in neutral position themachine is stopped. With arm 92 tilted either upwardly or downwardly thefilm is fed in a direction dependent upon the particular clutch which isengaged thereby.

It is to be noted that the light source, telescope tube and associatedparts are stationary, the aperture plate being moved to shift theposition of the scanning ray. The aperture plate is moved by the ratchetmechanism shown in Figs. 6, 8, l1

and 12 so as to shift the scanning ray from one film pastsaid gate, agear control mechanism whenever these strips engage the appropriate partof the sound gate. It is also evident that the sound gate may be ofother construction and shape. A round gate has been shown forconvenience inasmuch as it is adapted to receive the photoelectric celland also to serve as a guide for the film. In some instances it may bedesirable to omit part of the housing'in which case the photoelectriccell can be mountedL-in back of the film gate. The details ofconstruction and mounting of the telescope tube and the lens system mayalso be varied as desired. In Fig. 6 a particular mechanical connectionhas been shown for permitting the aperture plate to be shifted with thetelescope tube while maintaining driving engagement with gear I90, butit is evident that any other suitable driving connection which permitsof this relative adjustment may be employed.

Although certain details of construction and combination of parts havebeen specifically shown and described for purposes of illustrating theinvention it is to be understood that various changes and modificationmay be made therein as will be apparent to a person skilled in the art.The invention in accordance with the following claims when interpretedin view of the prior art.

The invention claimed is:

i. In a sound record apparatus for use with a film employing aphotographic sound track, a film gate, film feeding means for movingsaid train for actuating said film feeding means, reversible drive meansfor said film feeding means comprising a pair of driving shafts rotatingin opposite directions, a gear journaled on each shaft and in drivingengage ment with said gear train, a clutch associated with each of saidgears for selectively connecting the same in driving relation with thecorresponding driving shaft, means for actuating said clutches inunison. and in reverse directions so that the clutches are selectivelyengaged, and means for operating said clutches and said clutch achiatingmeans for reversing the direction of drive.

v 2. In a sound record apparatus for use with 2. him employing aphotographic sound track, a

gate, a pair of feed sprockets adapted to engage said film on oppositesides of said'gate, a gear train mechanically interconnectmg said icedsprockets for actuation in unison, reversible drive "means for saidsprockets comprising a pair of driving shafts rotating in oppositedirections, a gear fiournaleci on each shaft and in driving engagementwith said gear train, a clutch associated with each of said gears forselectively connecting the same in driving relation with thecorresponding driving shaft, means ior actuating said clutches in unisonand in reverse directions so that-the clutches are selectively engaged,and means for operating said clutches and said clutch actuating meansfor reversing the direction of drive.

3. In a sound record apparatus for use with a pm employing aphotographic sound track, a

111m gate, a pair of feed sprockets adapted to engage said film onopposite sides of said 'gate, a gear train mechanically interconnectingsaid feed sprockets for actuation in unison, reversible drive means forsaid sprockets comprising a pair of driving shafts rotating in oppositedirections, a gear iournaled on gagement' with said gear' train, aclutch assoeach shaft and in drivin enciated with each of said ears forselectively conis therefore to be limited only I necting the same indriving relation with the corresponding driving shaft, a pivoted armconnected to actuate reverse directions so that the clutches areselectively engaged, and a pair of electromagnets adapted when energizedto actuate said arm and ,said clutch for reversing the direction ofdrive.

4. In a sound record apparatus for use with a film employing aphotographic sound track, a film gate, a pair of feed sprockets adaptedto engage said film on opposite sides of said gate, a gear trainmechanically interconnecting said feed sprockets for actuation inunison, reversible drive means for said sprockets comprising a pair ofdriving shafts rotating in opposite directions, a gear iournaled on eachshaft and in driving engagement with said gear train, a clutchassociated with each of said gear for selectivelyconnecting the same indriving relation with the corresponding driving shaft, a pivoted armconnected to actuate said clutches in unison and in reverse directionsso that the clutches are selectively engaged, a pair of electromagnetsadapted when energized to actuate said arm for reversing the directionof drive, each of said electromagnets to hold the arm in position aftereach actuation thereof.

5. In a sound record apparatus for us with'a film employing aphotographic sound track, a film gate, a pair of feed sprockets adaptedto engage said film on opposite sides of said gate, a gear trainmechanically interconnecting said feed sprockets for actuation inunison, reversible drive means for said sprockets comprising a pair ofdriving shafts rotating in opposite directions, a

gagement with said gear train, a clutch associated with each of saidgears for selectively connecting the same in driving relation with thecorresponding driving shaft, a pivoted arm connected to actuate saidclutches in unison and in reverse directions so that the clutches areselectively engaged, a pair of electromagnets adapted when energized toactuate said arm for reversing the direction of drive, and means to holdsaid arm in neutral position for disengaging. both of said clutches.

'5. in a sound record apparatus for use with a film employingaphotographic sound track, a film gate, a pair of feed sprockets adaptedto engage said film on opposite sides of said ate, a gear trainmechanically interconnecting-said feed sprockets for actuation inunison, reversible drivemeans for said sprockets comprising a pair ofdriving shafts rotating in opposite directions, a gear Journaled on eachshaft and in driving engagement with said gear train, a clutchassociated with each of said gears for selectively connecting. the samein driving relation with the corresponding driving shaft, a pivoted armcon'- nected to actuate said clutches in unison and in reversedirections so that the clutches are selectively engaged, a pair ofelectromagnets adapted when energized to actuate said arm for reversingthe direction of drive, and means adapted to return said arm to neutralposition and hold said arm therein.

"I. In a sound record apparatus for use with a film employing aphotographic sound track, a film gate, a pair of feed sprockets adaptedto engage said film on opposite sides of said gate, a gear trainmechanically interconnecting said feed sprockets for actuation inunison, reversible drive means for, said sprockets comprising a pair ofdriving shafts rotating in opposite directions,

said clutches in unison and in and means associated with a gearjournaled on each shaft and in driving engagement with said gear train,a clutch associated with each of said gears for selectively connectingthe same in driving relation with the corresponding driving shaft, apivoted arm connected to actuate said clutches in unison and in reversedirections so that the clutches are selectively engaged, a pair ofelectromagnets adapted when energized to actuate said arm for reversingthe direction of drive, a device adapted to return said arm to neutralposition and hold said arm therein, and means to actuate said device.

8. In a sound record apparatus for use with a film employing aphotographic sound track, a film gate, a pair of feed sprockets adaptedto engage said film on opposite sides of said gate, a gear trainmechanically interconnecting said feed sprockets for actuation inunison, reversible drive means for said sprockets comprising a pin iondriving two shafts each being driven in opposite directions, a pair ofslidable gears 11 constant engagement with said gear train each havingconnected to it a first element clutch and means for selectivelyactuating said clutches in unison into driving engagement with itssecond element, a flywheel driving said second element and flexiblemeans driving said flywheel from said driven shaft, means for actuatingsaid clutches in unison and, in opposite directions for controlling thedirection of rotation of said feed sprockets.

9. In a sound record apparatus for use with a film employing aphotographic sound track, a. film gate, a pair of feed sprockets adaptedto engage said film on opposite sides of said gate,

, a gear train mechanically, interconnecting said feed sprockets foractuation in unison, reversible drive means for said sprocketscomprising a pair of driving shafts rotating in opposite directions, agear journaled on each shaft and in driving engagement with said geartrain, a clutch asso-- ciated with each of said gears for selectivelyconnecting the same in driven relation with the corresponding drivingshaft, a pivoted arm connected to actuate said clutches in unison and inreverse directions sothat the clutches are selectively engaged, meansfor actuating said arm to reverse the direction of drive, a frictiondisk driven by one of said driving shafts, a second a gear Journaled ineach shaft and in driving engagement with said gear train, a clutchassociated with each of said gears for selectively connecting the samein driving relation with the corresponding drivingv shaft, a pivoted armconnected to actuate said clutches in unison and in reverse directionsso that the clutches are selectively engaged, means for actuating saidarm to reverse the direction of drive, a friction disk in drivingrelation to one of said feed sprockets,

a second friction disk normally out of contact therewith, a gear drivenby one of said driving shafts, a flexible driveshaft interconnectingsaid last gear with said last friction disk, 9. pivoted bracket carryingsaid last disk, and means pivoting said bracket to hold said disks indriving engagement for rewind purposes.

11. In a sound record apparatus for use with a film employing aphotographic sound track, a film gate, a pair of feed sprockets adaptedto engage said film on opposite sides of said gate, a gear trainmechanically interconnecting said feed sprockets for actuation inunison, reversible drive means for said sprockets comprising a pair ofdriving shafts rotating in opposite directions, a gear journaled on eachshaft and in driving engagement with said gear train, a clutch asso--ciated with each of said'gears for selectively connecting the same indriving relation with the corresponding driving shaft, a pivoted armconnected to actuate said clutches in unison and I in reverse directionsso thatthe clutches are sefriction disk in driving relation with one ofsaid sprockets, said disks being normally out of engagement and means tohold said disks in en'- gagement for driving said sprockets at a speedgreater than normal for rewind purposes. 10. In a sound record apparatusfor use with a film employing a photographic sound track, a film gate, apair of feed sprockets adapted to engage said film on opposite sides ofsaid gate. a gear train mechanically interconnecting said feed sprocketsfor actuation in unison, reversible drive means for said sprocketscomprising a pair of driving shafts rotating in opposite directions,

lectively engaged, means for-actuating said arm to reverse the directionof drive, a friction disk in driving relation to one of said feedsprockets, a second friction disk normally out of contact therewith, agear driven by one of said driving shafts, a flexible driveshaftinterconnecting said last gear with said last friction disk, a pivotedbracket carrying said last disk, means pivoting said bracket to holdsaid disk in driving engagement for rewind purposes, and interlock meansto prevent actuation of said last means except when said clutches are indisengaged position.

12. In a sound record apparatus for use with film employing aphotographic sound track, a film gate, a pair of feed sprockets adaptedto engage said film on'opposite sides of said gate, a gear trainmechanically interconnecting said feed sprockets for actuation inunison, two gears mechanically engaged at ail times to saidinterconnected sprocket gears, two clutches associated with each of saidgears, means for sliding said 1

